RT4 User Interface issues when preheating

Two user interface design heuristics are to (1) Clearly show system state (Visibility of system state) and (2) keep the user in control.

When preheating in RT4 there is a small preheat indicator, but it way over in the upper right hand border of the window. I’d expect this to be above the main numerical data pane on the left. In addition the preheat temperature is not displayed anywhere. This violates the Visibility of System State heuristic.

Second, there is no apparent way to change the preheat temperature once the preheating has started. This violates the Keep the User in Control heuristic.

In this case, I wanted to use the main recipe for this bean, but slightly lower preheat because I am at the last 900g of beans.

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Hey @toddjohnson ,

Great feedback as usual. We will discuss in our meeting. Regarding #2 - it is not possible to change the preheat temp when you are already in Preheat mode. It must be set before entering Preheat. That is a limit of the firmware. I do agree that there should probably be an option to change it before entering the mode though.


Good feedback. We will add the target preheat temperature to the screen.
When using a recipe we don’t allow you to change the preheat. Easiest way would be to clone your recipe, change the pre-heat and start over.

And as Matthew mentioned, the firmware does not allow to change the preheat once it has started. We have had a few request to allow this as it is annoying to cycle through the states to start over…so it might be something we will work on in the future.


For the first roast with a Recipe you have to use what was set as Preheat when the Recipe was created/saved. But you can change the Preheat temp for the 2nd and later roasts using the Control Panel without having to alter your Recipe. So until Matt has a proper fix you can try this…

  • Launch the Recipe normally and Confirm the Preheat programmed in the Settings. Once it starts to Preheat…
  • Press PRS on the control panel
    – to go to Charge,
    – then again to go to Roast,
    – then again to End the Roast; the Cooling tray fan will start at C=9 (you only need to pause long enough between button presses to see that the f/w has responded)
  • Press F1 on the Control Panel which sets you up for a back-to-back roast and presents the opportunity to change the Preheat setting before starting
  • Press the +/- buttons above F1 to choose the Preheat temp you want
  • Press PRS to start Preheat at the temp you just selected with the same Recipe still running.

The Recipe will continue running if you choose to do additional Recipes- the programmed Preheat setting is only enforced the first time you do a roast with that Recipe. So the Recipe will continue with that temporary Preheat setting. And of course the Cooling tray fan is still running. For that you will have to use F2 to cycle to the Cooling tray fan and use the (-) button to set the Cooling tray fan to C=0 just to preserve your sanity.

It’s a lot of button pushing so if you screw it up just wind your way thru the process again using PRS to manage Mode. No data will be saved because the “Roast” doesn’t meet the minimum duration (4 minutes) to constitute a roast.

Alternately you can clone the Recipe, modify that clone to use the preheat you want for this special variation of the recipe, do that roast then just delete that cloned recipe after you’re done. If you think there’s a future need for that Recipe with the alternate Preheat youi’ll have to work out a new Title to distinguish between the 2 otherwise-identical Recipes.


@bab Just happened upon this again and had to laugh. If Don Norman were dead (he is not) he would be rolling in his grave over these instructions. I’m joking here, of course. Don Norman is one of the leaders in user interface design theory and at one time was VP of innovation at Apple. See here: Don Norman, co-founder and principal of Nielsen Norman Group

Full disclosure: I used to teach human factors engineering/user interface design and worked on one major project where Don was an advisor to our team. These days, I just use human factors theory in healthcare and teach a bit of it through my information visualization course.